The present invention relates to a power saving circuit of an LCD (Liquid Crystal Display) unit, and particularly to that according to VESA (Video Electronics Standards Association) standard.
For saving power consumption in a system having an LCD unit, there is a standby function, whereby the LCD unit is controlled in a standby mode with its display screen made inactive when no information is necessary to be displayed, and returned in a normal mode from the standby mode when there is any information to be displayed.
As an example of prior arts for realizing the standby function, there is a method disclosed in a Japanese patent application entitled "Crystal display control circuit" and laid open as a Provisional Publication No. 50996/'92.
In the prior art, an LCD unit is controlled in the standby mode or in the normal mode making use of a standby signal prepared exclusively for the purpose, and so, there must be provided a circuit and software for generating the standby signal, resulting in a high developing cost.